mirror of
https://github.com/golang/go
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e24977d231
The next CL will remove the -G flag, effectively hard-coding it to its current default (-G=3). Change-Id: Ib4743b529206928f9f1cca9fdb19989728327831 Reviewed-on: https://go-review.googlesource.com/c/go/+/388534 Reviewed-by: Keith Randall <khr@golang.org> Trust: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
106 lines
2.2 KiB
Go
106 lines
2.2 KiB
Go
// run
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// Copyright 2021 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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import (
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"fmt"
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)
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type AnyCacher[T any] interface {
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// Get an item from the cache. Returns the item or nil, and a bool indicating
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// whether the key was found.
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Get(k string) (T, bool)
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// Add an item to the cache, replacing any existing item.
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Set(k string, x T)
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}
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// Item ...
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type Item[T any] struct {
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Object T
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}
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// AnyCache implements AnyCacher
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type AnyCache[T any] struct {
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*anyCache[T]
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}
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type anyCache[T any] struct {
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items map[string]Item[T]
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janitor *janitor[T] // Needed for the failure in the issue
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}
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// Set adds an item to the cache, replacing any existing item.
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func (c *anyCache[T]) Set(k string, x T) {
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c.items[k] = Item[T]{
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Object: x,
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}
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}
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// Get gets an item from the cache. Returns the item or nil, and a bool indicating
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// whether the key was found.
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func (c *anyCache[T]) Get(k string) (T, bool) {
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// "Inlining" of get and Expired
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item, found := c.items[k]
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if !found {
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var ret T
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return ret, false
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}
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return item.Object, true
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}
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type janitor[T any] struct {
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stop chan bool
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}
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func newAnyCache[T any](m map[string]Item[T]) *anyCache[T] {
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c := &anyCache[T]{
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items: m,
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}
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return c
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}
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// NewAny[T any](...) returns a new AnyCache[T].
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func NewAny[T any]() *AnyCache[T] {
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items := make(map[string]Item[T])
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return &AnyCache[T]{newAnyCache(items)}
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}
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// NewAnyCacher[T any](...) returns an AnyCacher[T] interface.
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func NewAnyCacher[T any]() AnyCacher[T] {
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return NewAny[T]()
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}
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type MyStruct struct {
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Name string
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}
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func main() {
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// Create a generic cache.
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// All items are cached as interface{} so they need to be cast back to their
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// original type when retrieved.
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// Failure in issue doesn't happen with 'any' replaced by 'interface{}'
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c := NewAnyCacher[any]()
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myStruct := &MyStruct{"MySuperStruct"}
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c.Set("MySuperStruct", myStruct)
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myRawCachedStruct, found := c.Get("MySuperStruct")
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if found {
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// Casting the retrieved object back to its original type
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myCachedStruct := myRawCachedStruct.(*MyStruct)
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fmt.Printf("%s", myCachedStruct.Name)
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} else {
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fmt.Printf("Error: MySuperStruct not found in cache")
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}
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// Output:
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// MySuperStruct
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}
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